title: Subthalamic nucleus deep brain stimulation in primary cervical dystonia.
abstract: OBJECTIVE
  The globus pallidus internus (GPi) has been the primary target for deep brain stimulation (DBS) to treat severe medication-refractory dystonia. Some patients with primary cervical or segmental dystonia develop subtle bradykinesia occurring in previously nondystonic body regions during GPi DBS. Subthalamic nucleus (STN) DBS may provide an alternative target choice for treating dystonia, but has only been described in a few short reports, without blinded rating scales, statistical analysis, or detailed neuropsychological studies.
  
  
  METHODS
  In this prospective pilot study, we analyzed the effect of bilateral STN DBS on safety, efficacy, quality of life, and neuropsychological functioning in 9 patients with medically refractory primary cervical dystonia. Severity of dystonia was scored by a blinded rater (unaware of the patient's preoperative or postoperative status) using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) preoperatively and 3, 6, and 12 months postsurgery. Lead location, medications, and adverse events were also measured.
  
  
  RESULTS
  STN DBS was well-tolerated with no serious adverse effects. The TWSTRS total score improved (p < 0.001) from a mean (±SEM) of 53.1 (±2.57), to 19.6 (±5.48) at 12 months. Quality of life measures were also improved. STN DBS induced no consistent neuropsychological deficits. Several patients reported depression in the study and 3 had marked weight gain. No patients developed bradykinetic side effects from stimulation, but all patients developed transient dyskinetic movements during stimulation.
  
  
  CONCLUSIONS
  This prospective study showed that bilateral STN DBS resulted in improvement in dystonia and suggests that STN DBS may be an alternative to GPi DBS for treating primary cervical dystonia.
  
  
  METHODS
  This study provides Class III evidence that bilateral subthalamic nucleus deep brain stimulation results in significant improvement in cervical dystonia without bradykinetic side effects.
authors.affiliation: Department of Neurology, Surgical Movement Disorders, 1635 Divisadero Street, Fifth Floor, Suites 520-530, San Francisco, CA 94115, USA. jill.ostrem@ucsf.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Ostrem
authors.forename: C A
authors.initials: CA
authors.lastname: Racine
authors.forename: G A
authors.initials: GA
authors.lastname: Glass
authors.forename: J K
authors.initials: JK
authors.lastname: Grace
authors.forename: M M
authors.initials: MM
authors.lastname: Volz
authors.forename: S L
authors.initials: SL
authors.lastname: Heath
authors.forename: P A
authors.initials: PA
authors.lastname: Starr
mesh_terms: D000328:Adult; D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011788:Quality of Life; D018709:Statistics, Nonparametric; D020531:Subthalamic Nucleus / Q000502:physiology*; D014103:Torticollis / Q000523:psychology / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult